Test plug for oil cracking stills



TEST PLUG FOR OIL CRACKING STILLS Filed Dec. 14, 1955 dwdllNzNTOR Izaa T RNEY Patented July 28, 1936 UNITED STATES PATENT OFFICE TEST PLUG FOR OIL CRACKING STILLS New York Application December 14, 1935, Serial No. 54,395

Y 4 Claims. (01. 138-90) ers undergoing test or repairs and has for its object the provision of blanking means which are relatively simple, fully capable of sealing under any desired pressure, capable of being inserted in a minimum of time, and of a nature such that on even the largest stills. they may be inserted with a minimum of labor.

Tubular oil heaters designed for high pressure make use of tubes having an internal diameter of three of four inches, in the usual sizes. The pressure and temperature of operation may frequently be of thenature of 1000 F. and 1000 pounds per square inch. Cold test pressures must obviously be in excess of this level. Fittings for return bends, headers and elbows are large forgings and quite heavy. The tubes are normally secured intothese forgings by rolling. Individual parts of the box-fitting forgings are heavy and economical operation requires a minimum dis-- mantling of such parts for the insertion of blanking devices for test purposes. Speed in such operation is likewise essential, since time lost to such operations is unproductive and on large equipment unproductive time may be a major factor of operating cost. So far as I am aware, the best type of blanking device formerly available is one of heavy and complicated nature, normally requiring the services of about six trained men for a period of five hours or more to install. I have provided a more competent and simpler form of blanking or test device which may be inr stalled in a few minutes, and even in the heaviest sizes used on stills with the largest tubes, requires the services of only one or two men.

On stills of the type indicated, practically all fittings are of the box type for elbows, crossovers, and the like, and for frictionless return bends take the form in which a box is secured to the pipe and a return bend is fitted thereto and held by the box. In all of these fittings, the movable portions of the device such as plugs, return a bends, and the like, are held in place by pressure set-screws operating through a lock-block which in turn is secured to the fitting box by lugs cooperating with lugs or slotted extensions on the fitting box. I have taken advantage of this feature in devising my test blank.

In order that my invention may be understood, reference is made to the drawing which is attached -to and made a part of thisspecification. In this drawing, Figure 1 shows my novel test blank device, applied to a box fitting of an ordinary type, and Figure 2 shows a half side elevation of the fitting.

For greater clarity, the fitting alone will be explained first. Similar numbers are used for similar parts in both figures. The particular fitting shown here is a box elbow comprising a casting 3 into which tubes 4 and 5 are expanded. Inthe opening 6 the normal closure assembly used in this fitting is shown, consisting of a tapered plug 7 which fits the taper of the opening 6. This plug is kept in proper register by a key 8 which cooperates with a peg 9 on the body of casting 6. The casting 6 is extended outwardly to form a sleeve I0, a portion of which is cut away at I I. At several points upon the inside of sleeve l3, (four in this case), there are provided lugs I2, having a plane surface toward plug 1. A locking block I3 is provided, on which are lugs l4, which may be placed so as to bear against lugs l2 on sleeve I 0. Centrally of lock block l3 there is provided a set-screw [5, the end of which may be registered in a depression IE on the rear of the plug 1. When the lugs on the lock-block and sleeve are engaged and the set-screw l5 tightened, the plug 1 is firmly held in place. Other forms of lock-block and sleeve are common, such as a slotted sleeve, into the slots of which the lugs of the lock-block may pass, and the like. In most frictionless fittings, the elbow or return bend is held in place by similar lock-blocks and set screws cooperating with an upstanding sleeve which is aflixed to the tubes.

. All of these fittings of this type which make use of a lock-block and set-screw are capable of using my novel test blank, the variations necessary being only those which may be made by any skilled mechanic.

My improved test blank as shown in Figure 1 is composed of a head IT, to which a disc of lead or other soft metal I8, is secured by a hard metal disc 19 and several bolts 20. On the back of the head I! is a socket 2|, the internal portion of which is of sufiiciently great diameter, having a spherical bottom, so that stem 22 may fit loosely therein, and the spherical end of the stem 22, together with the loose fit will enable proper functioning withoutperfect alignment. The outboard portion of stem 22I isprovided with threads 23 of proper design to fit a lock-block l3, and the .end of stem 22 carries a wrench square or nut 24. To blank ofi tube 4, the lock-block and plug are removed from hole 30 opposite tube 4, lock-block l3 and stem 22 are assembled, head I! is'placed on stem 22, the lugs of. iii are placed in register with the lugs on I0, and the whole is drawn tight, the contact of the tube end and soft metal disc I8 forming a perfect seal competent to withstand any desired cold test pressure or steaming or other cleaning operation desired.

To permit of the introduction or withdrawal of cold test fluid, steam, and the like to the blanked ofi tubes a modified form of my test blank fit,- ting may be used, in which stem 22 is provided with a central passage 25, and wrench square" 24 is threaded at 26 so a pipe 21 may be inserted, on which may be mounted suitable fittings for the purpose intended, as, for instance, the angle valve etc., shown at 2B. In this case, head I1 is provided with passage 29 as shown in dotted lines. The contact of the spherical surfaces in socket 2! will provide a leak-proof joint at that point under the pressures used, and cold test liquid or steam may be introduced to or withdrawn from tube 4 through the passage thus provided.

Other modifications of this device will present themselves to the skilled mechanic, and I consider these within the scope of my invention, as limited and defined in the following claims. I claim: v I

1. A test blank device foruse with a high pressure still fitting making use of a lock-block and set-screw which comprises an elongated threaded shaft to replace said set-screw and cooperate with said lock-block, a blanking disc comprising a hard metal head and a softer metal contact surface aflixed thereto adapted for sealing contact with the end of the tube to be blanked, and means allowing unaligned contact of shaft and head whereby said head may be forced against the tube by pressure from said shaft, when set up in said lock-block. 1'

2.111 device as in claim 1 wherein theshaft and head are provided with a coextensive central passage for the admission of fluid to the blanked 01f tube. I

3. A test blank device for use with a high pressure still fitting making use of a lock-block and set-screw which comprises an elongated threaded stem to replace said set-screw and cooperate with said lock-block, a wrench square on the outboardend of said stem, the inboard end of said stem having a spherical shape, a blanking disc comprising a hard metal head, on the rear of said disc a socket to loosely receive said stem, a spherical bottom in said socket, and on the face of said disc a deformable metalcontact member adapted to make sealing contact with the end of the tube to be sealed.

4. A device as in claim 3 wherein the stem and blanking disc are provided with a coextensive central passage for the admission of fluid to the blanked ofi tube.

THOMAS M. BERRY. 

